Our company has the self-developed ITSM System.
and there are 2 terms in the system, CSR/SR.
Usually, the types of SR are 'Data Export/Changing Data/Questions about systems'
And CSR's types are mostly 'Change/Develop systems, Configuration mgmt'.

The PICs said CSR is 'Customer Service Request', SR is 'Service Request'.
but it's just acronym. nobody explain the difference CSR and SR clearly.
They said there are no specific definitions in our ITSM system. but it's very common structure.

I really don't understand it. What's the difference CSR and SR?
And do you really use both of them?

I don't think there is any difference- it is just two ways of referring to a Service Request.
The only difference I can think of is that one is a Catalogue Service Request- for an item in the Service Catalogue.
The other is a Service Request for something that is not in the catalogue.